There are many,you can book any hotel near ghats for 500-1000, so that you can witness morning Aarti at ghats. Moustache hostel, traveller hostel, gostops varanasi are some of the options in range. Enjoy your trip!
Try hostels instead of hotels , it will cost you less , and they have so many facilities even better than hotels sometimes and such a friendly environment , I recommend hostelworld.com for budget friendly hostels :)